/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.factories.datagen.types;

import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.functions.RuntimeContext;
import org.apache.flink.runtime.state.FunctionInitializationContext;
import org.apache.flink.runtime.state.FunctionSnapshotContext;
import org.apache.flink.streaming.api.functions.source.datagen.DataGenerator;
import org.apache.flink.table.data.GenericRowData;
import org.apache.flink.table.data.RowData;

/**
 * Data generator for Flink's internal {@link RowData} type.
 */
@Internal
public class RowDataGenerator implements DataGenerator<RowData> {

	private static final long serialVersionUID = 1L;

	private final DataGenerator<?>[] fieldGenerators;
	private final String[] fieldNames;

	public RowDataGenerator(DataGenerator<?>[] fieldGenerators, String[] fieldNames) {
		this.fieldGenerators = fieldGenerators;
		this.fieldNames = fieldNames;
	}

	@Override
	public void open(
		String name,
		FunctionInitializationContext context,
		RuntimeContext runtimeContext) throws Exception {
		for (int i = 0; i < fieldGenerators.length; i++) {
			fieldGenerators[i].open(fieldNames[i], context, runtimeContext);
		}
	}

	@Override
	public void snapshotState(FunctionSnapshotContext context) throws Exception {
		for (DataGenerator<?> generator : fieldGenerators) {
			generator.snapshotState(context);
		}
	}

	@Override
	public boolean hasNext() {
		for (DataGenerator<?> generator : fieldGenerators) {
			if (!generator.hasNext()) {
				return false;
			}
		}
		return true;
	}

	@Override
	public RowData next() {
		GenericRowData row = new GenericRowData(fieldNames.length);
		for (int i = 0; i < fieldGenerators.length; i++) {
			row.setField(i, fieldGenerators[i].next());
		}
		return row;
	}
}
